A comparative study of the ranging behaviour, activity rhythms and sociality of Lepilemur edwardsi (Primates, Lepilemuridae) and Avahi occidentalis (Primates, Indriidae) at Ampijoroa, Madagascar

Abstract

With 9 figures in the text)Lepilemur edwardsi and Avahi occideiitali.7 are both small, nocturnal folivores, but live sympatrically over a large part of their range, suggesting that niche differentiation has occurred. In order to establish whether ranging behaviour and activity patterns have contributed to niche differentiation, a field-study was carried out at Ampijoroa, Madagascar, within the area of range overlap. Four individuals of each species were fitted with radiocollars and tracked, dusk to dawn, over I8 months. Data were collected on home-range size, travel distances, activity and social behaviour. Neither showed the markedly biphasic activity patterns which have often been described for nocturnal prosimians; this might be explained by the combination offolivory and small body size. L. edwurdsi spent long periods inactive, but engaged in considerable social interaction during the night, including extensive long-range calling. The mean home range was I .09 ha, and ranges were rather evenly used. Home ranges of females overlapped extensively. and the range of the single adult male which could be caught overlapped with the ranges of several females, as is common in nocturnal prosimians. The mean nightly travel distance was very low. only 343 metres. On the other hand, social interactions in A. occidenrdis were primarily within a stable monogamous family unit, and long-range calling was very limited. Home ranges were rather larger than in L. edwurdsi, but less evenly used, and mean nightly travel distances were much greater, 117.5 m. Differences in range-use patterns may be explained by the contrast between Avuhi's selective feeding on relatively high-quality young leaves and flowers, versus Lepilemur edrrardsi's unselective feeding on relatively low-quality, but ubiquitous and evenly-distributed. mature and old leaves. Similarly, while overlapping female ranges may be adequate when food resources are evenly distributed, monogamy in Avahi may be a response to selective feeding on a patchy food resource.

Terrestriality and bacterial transfer: a comparative study of gut microbiomes in sympatric Malagasy mammals

“…Caecotrophy-reingestion of feces-has been observed in one sportive lemur species (L. mustelinus) and may be an adaptation to increase nitrogen utilization [81]. However, caecotrophy has not been observed in our study species (L. ruficaudatus) or other sportive lemurs [84,88,89]. Instead, they may manage their folivorous diet and small body size by conserving energy; they have one of the lowest basal metabolic rates among folivorous mammals [90] and long nighttime resting periods [81,88].…”

“…However, caecotrophy has not been observed in our study species (L. ruficaudatus) or other sportive lemurs [84,88,89]. Instead, they may manage their folivorous diet and small body size by conserving energy; they have one of the lowest basal metabolic rates among folivorous mammals [90] and long nighttime resting periods [81,88]. Although sifaka and sportive lemurs are both hindgut fermenters, their digestive strategies lie at opposite ends of the continuum observed for primates.…”

“…Sifaka are diurnal with a body mass of 2.5-4 kg [44], while sportive lemurs are remarkably small-bodied (<1 kg) for a folivorous species [88]. Large body size is considered a morphological adaptation to folivory, providing increased gastrointestinal surface area and retention time for nutrient absorption [67].…”

Allogrooming in Male-Female Pairs of Captive Owl Monkeys (Aotus nancymaae)

“…Our estimated rates of allogrooming in captive A. nancymaae are similar to or even greater than that of nocturnal strepsirrhines (Lepilemur edwardsi, Avahi occidentalis [Warren and Crompton, 1997]). In addition to being nocturnal, owl monkeys are insectivorous [Wright, 1985].…”

Duetting—A mechanism to strengthen pair bonds in a dispersed pair‐living primate (Lepilemur edwardsi)?

“…Sportive lemurs are predominantly folivorous (Smith and Jungers, 1997). Toward the end of the dry season when trees become nearly bare of leaves, food may be expected to exert a selective pressure (Hladik, 1980) and competition for food resources increases (Warren and Crompton, 1997). Indeed, a study of the closely related, folivorous Lepilemur ruficaudatus (Ganzhorn, 2002) revealed that differences in body mass variation and food requirements of both sexes during the year indicate severe nutritional constraints for females during the period of lactation.…”